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ABSTRACT: The purpose of our study was to evaluate the MRI appearance of phyllodes breast tumors and to differentiate them from fibroadenomas.
MR images were obtained on a 1.5-T imager. T1- and T2-weighted sequences and dynamic 2D fast-field echo T1-weighted sequences were performed. MR images of 23 patients with 24 phyllodes breast tumors (one malignant, 23 benign) were analyzed with respect to morphology and contrast enhancement. The tumors were compared with the MRI appearance of 81 fibroadenomas of 75 patients.
Well-defined margins were seen in 87.5% of the phyllodes tumors and 70.4% of the fibroadenomas, and a round or lobulated shape in 100% and 90.1%, respectively. A heterogeneous internal structure was observed in 70.8% of phyllodes tumors and in 49.4% of fibroadenomas. Nonenhancing internal septations were found in 45.8% of phyllodes tumors and 27.2% of fibroadenomas. A significantly greater increase in signal was seen on T2-weighted images in the tissue surrounding phyllodes tumors (21%) compared with fibroadenomas (1.2%). Most of both lesions appeared with low signal intensity on T1- and T2-weighted images. After the administration of contrast material, 33.3% of phyllodes tumors and 22.2% of fibroadenomas showed a suspicious signal intensity-time course.
Phyllodes breast tumors and other fibroadenomas cannot be precisely differentiated on breast MRI. Phyllodes tumors have benign morphologic features and contrast enhancement characteristics suggestive of malignancy in 33% of cases.
American Journal of Roentgenology 12/2005; 185(5):1317-21. · 2.78 Impact Factor
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ABSTRACT: OBJECTIVE: Our objective was to increase the accuracy of breast MRI using a semiquantitative analysis of typical MRI features and their diagnostic potential. The prevalence of recently reported MRI signs of breast lesions were analyzed and compared with other well-known signs. CONCLUSION: New MRI features, especially from T2-weighted images, are promising for more reliable and accurate interpretation of breast lesions. Prospective studies of these findings are required to define cut-off values and test clinical practicality.
American Journal of Roentgenology 11/2005; 185(4):964-70. · 2.78 Impact Factor
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ABSTRACT: This study was conducted to assess the clinical impact of breast density and density of the lesion's background on the performance of a computer-aided detection (CAD) system in the detection of breast masses (MA) and microcalcifications (MC).
A total of 200 screening mammograms interpreted as BI-RADS 1 and suspicious mammograms of 150 patients having a histologically verified malignancy from 1992 to 2000 were selected by using a sampler of tumor cases. Excluding those cases having more than one lesion or a contralateral malignancy attributable to statistical reasons, 127 cases with 127 malignant findings were analyzed with a CAD system (Second Look 5.0, CADx Systems, Inc., Beavercreek, OH). Of the 127 malignant lesions, 56 presented as MC and 101 presented as MA, including 30 cases with both malignant signs. Overall breast density of the mammogram and density of the lesion's background were determined by two observers in congruence (density a: entirely fatty, density b: scattered fibroglandular tissue, density c: heterogeneously dense, density d: extremely dense).
Within the unsuspicious group, 100/200 cases did not have any CAD MA marks and were therefore truly negative (specificity 50%), and 151/200 cases did not have any CAD MC marks (specificity 75.5%). For these 200 cases, the numbers of marks per image were 0.41 and 0.37 (density a), 0.38 and 0.97 (density b), 0.44 and 0.91 (density c), and 0.58 and 0.68 (density d) for MC and MA marks, respectively (Fisher's t-test: n.s. for MC, p < 0.05 for MA). Malignant lesions were correctly detected in at least one view by the CAD system for 52/56 (92.8%) MC and 91/101 (90.1%) MA. Detection rate versus breast density was: 4/6 (66.7%) and 18/19 (94.7%) (density a), 32/33 (97.0%) and 49/51 (96.1%) (density b), 14/15 (93.3%) and 23/28 (82.1%) (density c), and 2/2 (100%) and 1/3 (33.3%) (density d) for MC and MA, respectively. Detection rate versus the lesion's background was: 19/21 (90.5%) and 36/38 (94.7%) (density a), 34/36 (94.4%) and 59/62 (95.2%) (density b), 8/9 (88.9%) and 20/24 (83.3%) (density c), and 9/10 (90%) and 4/8 (50%) (density d) for groups 2 and 3, respectively. Detection rates differed significantly for masses in heterogeneously dense and extremely dense tissue (overall or lesion's background) versus all other densities (Fisher's t-test: p < 0.05). A significantly lowered FP rate for masses was found on mammograms of entirely fatty tissue.
Overall breast density and density at a lesion's background do not appear to have a significant effect on CAD sensitivity or specificity for MC. CAD sensitivity for MA may be lowered in cases with heterogeneously and extremely dense breasts, and CAD specificity for MA is highest in cases with extremely fatty breasts. The effects of overall breast density and density of a lesion's background appear to be similar.
Journal of Digital Imaging 09/2005; 18(3):227-33. · 1.25 Impact Factor
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ABSTRACT: The aim of this study was to investigate the feasibility and the precision of magnetic resonance (MR)-guided large-core breast biopsies (LCBB) by using the second prototype of an automatic system (ROBITOM II), which is used to localize lesions while operating at the isocenter of a 1.5-T whole-body scanner.
In comparison to the first prototype, ROBITOM II is equipped with a dedicated double breast coil and a high-speed trocar setting unit. In vitro experiments (n = 25) with grapefruit phantoms, which contained multiple vitamin E capsules (12 x 7 mm in size) as artificial lesions, were performed. Four patients with MR-detectable breast lesions underwent biopsy. A trocar was positioned in front of the lesion and inserted into the breast. Specimens were harvested with a coaxial technique by using a 14-G core needle biopsy gun.
In all 25 in vitro experiments, capsule material was detected in the specimen cylinder. In 4 patients, the coaxial needle was detected exactly at the expected position. Between 8 and 16 tissue cylinders were harvested. Histologic evaluation resulted in 1 invasive ductal carcinoma and 1 papilloma, which were confirmed after open surgery. One patient who had a proven breast cancer was biopsied for exclusion of multifocal disease. She showed fibrocystic changes, whereas open surgery revealed 3 small areas of ductal carcinoma in situ (DCIS). Another patient showed fibroadenoma after biopsy. This patient is in the follow-up period, which has lasted between 3 and 4 months up until now.
In this pilot patient study, the feasibility of manipulator-assisted large-core breast biopsy inside a 1.5-T whole-body scanner was demonstrated by using ROBITOM II. The precision of the device was confirmed with in vitro experiments. Although these findings are preliminary and the follow-up period is rather short, they nevertheless represent a successful proof-of-principle of LCBB with ROBITOM II.
Investigative Radiology 08/2005; 40(7):458-63. · 4.59 Impact Factor
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ABSTRACT: The purpose of this study was to investigate the feasibility, efficacy, and safety of ultrasound-guided percutaneous cryotherapy of stage T1 breast cancers.
Thirty patients with biopsy-confirmed breast cancers with tumor diameters of 15 mm or smaller (range, 5-15 mm; median, 12 mm) underwent cryotherapy. After local anesthesia, a 3-mm cryo probe was placed into the tumor under ultrasound guidance. All tumors were subjected to 2 freeze cycles with an interposing thawing cycle. The size of the ice-balls, their distance to the skin, and the temperature at the tip of the probe were closely monitored during the procedure. The patients underwent surgery within 6 weeks and the specimens were evaluated histologically.
The median minimum temperature reached -146 degrees C (range, -117 degrees C to -167 degrees C). In 5 of 29 patients, remnant ductal carcinoma in situ was detectable histologically after cryotherapy beyond the margin of the cryosite in the specimens after open surgery. In 24 patients, no viable tumor cells were found. No severe side effects occurred. In one patient, the cryo procedure was not performed completely because of technical problems.
Percutaneous cryotherapy is a feasible and safe procedure in minimally invasive therapy for small breast cancers. Residual ductal carcinoma in situ may be attributable to the beginning of a learning curve or by false-negative detection in pre-interventional imaging. Magnetic resonance mammography might aid in treatment planning and for therapy monitoring to better define target tissue and to correlate the tumor margin with the ice-ball.
Investigative Radiology 08/2005; 40(7):472-7. · 4.59 Impact Factor
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ABSTRACT: We report the case of a femoral vein cannulation in a critically ill trauma patient with the malposition of a large-bore central venous catheter in the urinary bladder. Recognition of the malposition was hampered by bloody tamponade of the bladder in the context of blunt thoraco-abdominal trauma with kidney and liver laceration. A high index of clinical suspicion and the institution of adequate therapy were the key to achieving a successful clinical outcome. We discuss the anatomy of femoral veins, including their close relation to a distended bladder. The application of ultrasound even in emergency situations is stressed.
European Journal of Emergency Medicine 01/2005; 11(6):351-4. · 0.90 Impact Factor
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ABSTRACT: To evaluate the rate of unnecessary follow-up procedures recommended by radiologists using a CAD-system.
185 patients (740 images) were consecutively selected from three groups (36 histologically proven cancers = group 1; 49 histologically proven benign lesions = group 2 and 100 screening cases (4 years-follow up = group 3). Mammograms were evaluated by a CAD system (Second Look, CADx, Canada). Five blinded radiologists assessed the images without/with CAD outputs. Diagnostic decisions were ranked from surely benign to surely malignant according to BIRADS classification, follow-up procedures were recommended for each observed lesion (a, screening; b, short interval follow-up examination in 6 months; c, pathologic clarification).
CAD-system detected 32/36 cancers (88.9%) (FP-rate: 1.04 massmarks and 0.27 calcmarks/image). The following values were reached by all observers without/with CAD in the mean: Sensitivity 80.6/80.0%, specificity 83.2/86.4%, PPV 53.1/58.1%, and NPV 94.6/94.7%. Observers described a similar number of additional lesions without/with the use of CAD (325/326). Whereas the number of unnecessary short-time follow up recommendations increased in all case-subgroups with CAD: 40.8/42.9% (group 1), 35.6/38.1% (group 2), 44.7/46.8% (group 3), respectively, the number of recommended biopsies decreased in all subgroups: group 1: 34.7/27.1%; group 2: 47.4/41.5%, group 3: 33.3/22.0%, respectively.
In this rather small population additional usage of CAD led to a lower rate of unnecessary biopsies. The observed decrease of recommended unnecessary biopsies due to the usage of CAD in the screening group suggests a potential financial benefit by using CAD as diagnostic aid.
European Journal of Radiology 08/2004; 51(1):66-72. · 2.61 Impact Factor
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ABSTRACT: The aim of the present article is to investigate effects of hormone replacement therapy (HRT) on contrast medium enhancement patterns in postmenopausal patients during magnetic resonance mammography (MRM).
Two hundred and fifteen patients receiving hormonal medication were divided into four groups: 150 patients with 1 MRM during HRT (group A), 13 patients with 2 MRMs under HRT (group B), 30 patients with 1 MRM during HRT and 1 MRM after HRT withdrawal (group C), and 22 women with 1 MRM after HRT withdrawal (group D). Dynamic MRM was performed at 1.5 Tesla. Signal intensity changes were characterized by five time curves: minimal enhancement (type I), weak continuous enhancement (type II), strong continuous enhancement (type III), and a steep initial slope followed by a plateau phenomenon (type IV) or a washout effect (type V).
Of all 193 patients under HRT (group A + group B + group C), 60 patients (31.1%) showed curve type I, 88 patients (45.6%) showed type II and 45 patients (23.3%) showed type III. There were significant differences to 52 patients after HRT withdrawal (group C + group D) (P < 0.0001), with 42 patients (80.8%) for curve type I, 8 patients (15.4%) for type II, and 2 patients (3.8%) for type III. In both MRM sessions in group B, 69% of the patients showed identical curve types without significant differences (P = 0.375). In group C, 28 of 30 patients (93%) dropped to lower curve types with significant differences in curve types during and after HRT (P < 0.0001).
The majority of patients receiving postmenopausal HRT showed bilateral symmetrical, continuous enhancement without evidence of a plateau phenomenon or a washout effect due to HRT in MRM. Hormonal effects could be proven and were reproducible and reversible.
Breast cancer research: BCR 01/2004; 6(3):R232-8. · 5.24 Impact Factor
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ABSTRACT: Cancer cells exhibit altered local dielectric properties which can be assessed using electrical impedance scanning (EIS). The study was aimed at clarifying influence of lesion size and depth on EIS performance. From a series of 387 lesions (129 malignant and 258 benign) from 363 patients being sonographically and/or mammographically evaluated, size and depth information was not available in 112 lesions, size was available in 86 lesions and additional depth information was available in 189 lesions, respectively, while performing EIS. Lesions were either histologically verified or had a follow-up of at least 2 years. One hundred three of 129 malignant lesions and 165 of 258 benign lesions were correctly detected (sensitivity 79.8%, specificity 64.0%, accuracy 71.9%). Sensitivity without knowledge of size and depth was 64.6% (10 of 16 malignant lesions detected). This value increased to 76.2% (32 of 42) with knowledge of the size and further increased to 85.9% with knowledge of size and depth (61 of 71). Specificity values in the three subgroups were almost similar: 64.6 (62 of 96), 65.9 (29 of 44), and 62.7% (74 of 118), respectively. Accuracy rises from 63.6% (without knowledge of size/depth) to 71.1 and 74.3% (with size knowledge and with size and depth knowledge, respectively). Accuracy of EIS improved significantly by including sonographical information about depth and size into the analysis. Ultrasound examination should be performed prior to EIS.
European Radiology 12/2003; 13(11):2441-6. · 3.22 Impact Factor
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ABSTRACT: To evaluate associations between histopathologic findings, tumor size, and detection rate of malignant mammographic findings by using a computer-aided detection (CAD) system.
The study included 208 mammographically detected histologically proven malignant breast lesions in 208 women. Findings were 150 masses and 114 microcalcifications; 56 lesions showed both findings; 94 lesions, mass only; and 58 lesions, microcalcification only. CAD was used to evaluate mammograms in two views retrospectively. Also, corresponding histopathologic findings and lesion size were evaluated. CAD marks were considered positive if, on at least one view, they correctly identified the corresponding mammographic lesion location.
Ninety percent (135 of 150) of masses and 93.0% (106 of 114) of microcalcifications were marked correctly by the CAD system. Overall tumor detection rate was 93.8% (195 of 208). Size-related detection rate for masses was 83.3% (25 of 30) for lesions up to 10 mm, 100% (45 of 45) for lesions 11-20 mm, 100% (46 of 46) for lesions 21-30 mm, 83.3% (10 of 12) for lesions 31-40 mm, and 52.9% (nine of 17) for lesions larger than 40 mm. Size-related tumor detection rate for microcalcifications was 92.5% (37 of 40) for microcalcifications up to 10 mm, 93.1% (27 of 29) for lesions 11-20 mm, 100% (20 of 20) for lesions 21-30 mm, 87.5% (seven of eight) for lesions 31-40 mm, and 88.2% (15 of 17) for larger microcalcifications. Detection rates for mammographically visible masses (invasive ductal carcinoma, invasive lobular carcinoma, invasive tubular carcinoma, noninvasive cancers, mucinoid cancers, and others) were 92.3% (84 of 91), 89.3% (25 of 28), 75.0% (six of eight), 100% (15 of 15), 33.3% (one of three), and 80.0% (four of five), respectively. Detectability rates for mammographically visible areas suspicious for microcalcifications (invasive ductal carcinoma, invasive lobular carcinoma, invasive tubular carcinoma, and noninvasive cancers) were 92.3% (60 of 65), 100% (eight of eight), 100% (five of five), and 91.9% (31 of 34), respectively. Highest overall detection rates were observed for invasive ductal carcinomas (96.6% [112 of 116]) and noninvasive cancers (92.9% [39 of 42]).
Highest detection rates were observed for 10-30-mm tumor masses and for invasive ductal carcinomas and noninvasive cancers.
Radiology 10/2003; 228(3):851-6. · 5.73 Impact Factor
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ABSTRACT: To investigate a robotic manipulator system for MR-guided breast biopsies inside a 1.5 T whole-body magnet.
Fourteen patients with suspicious breast lesions (diameter 18.6 +/- 12 mm) underwent biopsy. Patients with malignant findings underwent surgery afterwards and the histologic findings between biopsy and surgery were correlated.
In five patients biopsy findings were histopathologically confirmed following open surgery. One tubular carcinoma was missed; one invasive cancer was underestimated. Seven patients with benign findings are still in the follow-up period.
The study demonstrates the feasibility to perform breast biopsies inside the magnet of a whole-body MR scanner by using a manipulator system.
Journal of Magnetic Resonance Imaging 05/2003; 17(4):493-8. · 2.70 Impact Factor
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Journal of Clinical Ultrasound 02/2003; 31(1):59-60. · 0.81 Impact Factor
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ABSTRACT: The aim of this study was to compare the performance of a dedicated double breast coil for MR imaging and intervention with a standard diagnostic double breast coil.
Signal-to-noise ratios (SNRs) were determined for both coils by using a water phantom. Fourteen patients were examined, 11 underwent preoperative hookwire localization, two were biopsied, and one received diagnostic imaging. Breast images were acquired in three patients with both coils and were visually compared. Harvested specimen from the biopsies and surgeries following hookwire localization were histopathologically evaluated.
SNR was superior with the interventional coil in the posterior (axillary) part of the imaging volume and inferior in the anterior part compared with the standard coil. Anatomic MR breast images were of similar diagnostic quality. For the two biopsy procedures the trocar was correctly placed in front of the suspicious lesion. Hookwires were correctly located inside the lesion in nine patients and in contact with the lesion in one patient. In one patient a 2 mm distance between the lesion and the wire was observed.
Diagnostic imaging followed by subsequent MR-guided intervention is possible within a single session by using the dedicated interventional coil. The correct final position of the hookwires demonstrates the precision of the MR guided localization procedure.
Investigative Radiology 02/2003; 38(1):1-8. · 4.59 Impact Factor
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ABSTRACT: The present study investigated the clinical application of magnetic resonance (MR)-guided breast interventions, such as manipulator-assisted large core breast biopsy (LCBB) inside a 1.5 T whole-body magnet and MR-guided interstitial laser therapy (ILT). Sixteen patients underwent LCBB and 1 additional patient underwent 4 sessions of ILT of a recurrent undifferentiated lymph node metastasis in the axilla using a Nd-YAG laser (1064 nm). Temperature changes of the tumor tissue during ILT were monitored using phase images of a gradient echo sequence (GRE) (TR/TE/FA = 25/12/30). In 5 patients the biopsy findings were histopathologically confirmed after open surgery. In 3 patients, the biopsy missed one tubular and one ductal carcinoma; one invasive carcinoma was underestimated. Eight patients with benign findings are still in the follow-up period. The heating zone during ILT was well delineated on subtracted phase images. No severe adverse events were observed with LCBB or ILT. MR-guided breast biopsies are feasible with the manipulator system inside a whole-body 1.5 Tesla MR scanner. GRE information is suitable for therapy monitoring during ILT within the tumor. Further studies are necessary to evaluate the accuracy of the manipulator system and the efficacy of ILT in the treatment of breast lesions.
Zeitschrift für Medizinische Physik 02/2003; 13(3):198-202. · 1.21 Impact Factor
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ABSTRACT: The aim of this study was to investigate the potential and feasibility of ultrasound-guided cryotherapy in breast cancer. Fifteen female patients with 16 breast cancers (mean tumour diameter 21+/-7.8 mm) were treated. A 3-mm cryo probe was placed in the tumour under ultrasound guidance. Two freeze/thaw cycles with durations of 7-10 min and 5 min, respectively, were performed. The size of the iceballs was measured sonographically in 1-min intervals. The patients underwent surgery within 5 days and the specimens were evaluated histologically. The mean diameter of the iceball was 28+/-2.7 mm after the second freezing cycle. No severe side effects were observed. Five tumours with a diameter below 16 mm did not show any remaining invasive cancer after treatment. Two of these had ductal carcinoma in situ (DCIS) in the surrounding tissue. In 11 patients cryotherapy of tumours reaching diameters of 23 mm or more resulted in incomplete necrosis. This study shows that the invasive components of small tumours can be treated using cryotherapy. Remnant DCIS components which may not be detected preinterventionally represent a challenging problem for complete ablation. In tumours larger than 15 mm two or more cryo probes should be used to achieve larger iceballs.
European Radiology 01/2003; 12(12):3009-14. · 3.22 Impact Factor
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ABSTRACT: The introduction of the Full Field Digital Mammography (FFDM) opens the way to a large range of future advanced applications. Among them, Contrast Enhanced Digital Mammography (CEDM) could be a fast and less expensive alternative to Magnetic Resonance Imaging (MRI) for breast lesion characterization. In this work, we have investigated, first on phantom then on patients, the capability of a modified FFDM system to show the contrast enhancement of lesions after intra-venous injection of iodine. The uptake has been estimated from the difference between pre- and post-contrast images. Phantom results showed that 1) detectability thresholds of the contrast media were compatible with clinical conditions; 2) breast radiological thickness has a low impact on uptake detectability; 3) spatial and temporal analysis showed delayed margin contrast uptake of the simulated lesion and slow increase of contrast in the background. Preliminary results on patients have confirmed the phantom results and have shown a contrast uptake in all malignant lesions despite the observed patient motion artifacts, and some moderate signal variability. This study demonstrated the feasibility of the Contrast Enhanced Digital Mammography technique. Further investigations and clinical validations will have to be completed before it can be widely used in a daily routine practice.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
05/2002;
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ABSTRACT: The aim of this study was to determine the tumour detection rate and false positive rate of a new mammographic computer-aided
detection system (CAD) in order to assess its clinical usefulness. The craniocaudal and oblique images of 150 suspicious mammograms
from 150 patients that were histologically proven to be malignant were analysed using the Second Look CAD (CADx Medical Systems,
Quebec, Canada). Cases were selected randomly using the clinic's internal tumour case sampler. Correct marking of the malignant
lesion in at least one view was scored as a true positive. Marks not at the location of the malignant lesion were scored as
false positives. In addition, mammograms with histologically proven benign masses (n=50) and microcalcifications (n=50), as well as 100 non-suspicious mammograms, were scanned in order to determine the value of false-positive marks per image.
The 150 mammograms included 94 lesions that were suspicious due to masses, 26 due to microcalcifications and 30 showed both
signs of malignancy. The overall sensitivity was 90.0% (135 of 150). Sensitivity on subsets of the data was 88.7% (110 of
124) for suspicious masses (MA) and 98.2% (55 of 56) for microcalcifications. Eight of 14 false-negative cases were large
lesions. The overall false-positive rate was observed as 0.28 and 0.97 marks per image of microcalcifications and masses,
respectively. The lowest false-positive rates for microcalcifications and MA were observed in the cancer subgroup, whereas
the highest false-positive rates were scored in the benign but mammographically suspicious subgroups, respectively. The new
CAD system shows a high tumour detection rate, with approximately 1.3 false positive marks per image. These results suggest
that this system might be clinically useful as a second reader of mammograms. The system performance was particularly useful
for detecting microcalcifications.
European Radiology 01/2001; 11(12):2454-2459. · 3.22 Impact Factor
